Plate condenser element and method of manufacture therefor



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c. T. ALLCUTT PLATE CONDENSER ELEMENT AND METHOD OF MANUFACTURE THEREFOR Filed Dem 1a, 1919 w INVENTOR WITNESSES:

Patented Aug. 10, 1926.

UNITED STATES PATENT OFFICE.

CHESTER T. ALLCUTT,OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR T WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

PLATE CONDENSER ELEMENT AND METHOD OF MANUFACTURE THEREFOR.

Application filed December 13, 1919.

My invention relates to plate-condenser elements, and it has for its object to provide apparatus of the character designated that shall be simple and rugged in construction,

6 and that shall have especially accurate spacing of the plate members.

Another object of my invention is to provide a method of manufacture of a plate element which shall be simple, inexpensive and readily applicable to quantity manufactured by relatively unskilled labor.

In the accompanying drawing, Fig. 1 is a fragmentary side view, partially in section and partially in elevation, of the members of a condenser element, together with certain apparatus employed in the assembly, thereof, and Fig. 2 is a similar view of a completed condenser element.

Electrical condensers of the plate type are now Widely used, particularly in connection with wireless telegraphy and telephony and, in their usual form, comprise a stack of Spaced plates mounted in inter-leaved relation with another similar stack, together with means for causing relative movement between the two stacks without causing contact between the elements of one stack and the elements of the other stack. By this movement, the condensance of the device may be adjusted and, in order that this adjustment may be smooth and uniform, and

without danger of short-circuiting, it is essential that the relative movement of the elements shall be in planes exactly parallel to the plate elements themselves, so that the thickness of the dielectric shall remain substantially contant.

The above results have been secured hitherto by employing great care in the construction of the device, skilled workmen employing very accurate tools and manipulation in order to secure the desired operation. These conditions have caused apparatus of the character designated to be expensive and to have a limited quantity production.

In accordance with my invention, I as semble the plates of a condenser element in the desired relative relationship, with wash ers or other spacing members therebetween formed of soft material, such, for example, as lead and having athickness slightly greater than that desired between the plates in the completed condition. Temporary steel spacing members of very accurate di-' mensions and having a thickness equal to Serial No. 344,739.

the desired space between the plates are then placed in proximity to the soft metal spacers, and the entire stack is crushed by a suitable press until the pressure is taken up by the temporary spacers, the spacers being 00 stressed beyond the elastic limit. The tem porary spacers are then removed and it will be found that the completed structure conforms very closely to the desired mechanical and electrical operating requirements.

Referring to the drawing for a more detailed understanding of my invention, I show a plurality of plate members at 5 in Fig. 1, these members being formed of suit- I able material and having any desired shape, depending upon the nature of the finished condenser. These plates are stacked upon a fastening member, such as a bolt 6, with washers or other spacing members 77 therebetween, these spacing members being formed of lead or similar soft material, and having a thickness slightly greater than the thickness of the space ultimately desired between the plates 5-5.

Temporary spacing members 88 formed, 1 for example, of steel and accurately machined to a thickness equal to the thickness of the space ultimately desired between the plates 55, are then placed in proximity to the spacing members 77 and the entire assembled stack is then placed in a press indicated by an anvil 9 and a plunger 10, these press members being properly recessed so as not to engage the bolt 6.

The press is now operated to crush the ena tire stack, flattening the soft-metal washers 77 until the pressure is taken up by the thinner spacing members 88. The pressure is now removed and a nut placed on the bolt 6, as shown in Fig. 2, whereupon the temporary spacing members 88 may be re moved. It will now be found that the plates 55 are very accurately spaced from each other in parallel planes and that they are so firmly seated upon the crushed soft-metal l spacers that they do not tend to become loosened, even with long continued use and vibration.

The completed stack may now be either fixedly or movably mounted in inter-leaved relation with other similar stacks, and the. whole employed either in air or immersed in oil, all as is well understood in the art.

While I have shown my invention in a simple and preferred form, it will be obrious to those skilled in the art that it is susceptible of Various minor changes and alterations without departing from the spirit thereof. I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art, or specifically act forth in the appended claim.

I claim as my invention The method of constructing a condenser element comprisinga plurality of metal plates spaced apart by spacing members formed of softer material than the plates themselves, which comprises stacking the plates with permanentso'tt metal spacers therebetween of slightly greater thickness than the desired ultimate thickness of the space between the plates, inserting temporary spacers adjacent said permanent spacers, and having a thickness equal to the desired ultimate thickness of the spaces between the plates, applying pressure to the entire stack until the soft metal spacers are crushed to such an extent that the pressure is taken up by the temporary spacers and removing the temporary spacers.

In testimony whereof, I have hereunto subscribed my name this 25th day of November, 1919.

CHESTER T. ALLCUTT. 

